Police closed off the area surrounding Manchester Arena, and performed a controlled explosion on a suspicious item that turned out to be an abandoned article of clothing. The venue holds as many as 20,000 people, according to CNN.

We are working to provide a number for anyone concerned about loved ones to contact which will be released as soon as possible

“Ariana Grande had left, the lights had come up, everyone was just getting out of their seats and walking toward the stairs when all of a sudden this huge sound, which sounded like an explosion, went off,” Karen Ford, who was attending the concert with her daughter, told BBC.